cryptobone is the graphical user interface for a secure messaging system that makes sure a user's email is always encrypted without burdening the user with complex message key management. Based on a separate daemon, both ease-of-use and security are assured by a novel approach to encryption key management.

While the message keys are secured by a daemon running on the Linux machine, additional protection can be achieved by using an external device for storing the encryption keys. This external device can be another Linux computer dedicated to this task or a Beagle Bone or a Raspberry Pi.

The Crypto Bone secure messaging system automatically encrypts a message with a strong message key, stored in the cryptobone daemon's data base for secrets. Except for an initial registration of a message key for a recipient, the user does not need to remember any of these message keys being in use, as the system updates keys when messages are sent out or received.

While only strongly encrypted messages are sent out, incoming messages that cannot be decrypted with registered message keys are discarded.

In order to transfer encrypted messages the system has to be set up with a working email account used for this purpose only.

cryptobone has been written by Ralf Senderek <innovation@senderek.ie>.
The core cryptographic library libclr.so which is used by the cryptobone daemon
has been written by Peter Gutmann <pgut001@cs.auckland.ac.nz>.